This invention relates generally to communication systems and particularly to establishing links between individuals on a wireless communication network.
A mobile ad hoc network (MANET) is an autonomous system of mobile routers and associated hosts connected by wireless links, the union of which forms an arbitrary graph. The routers are free to move randomly and organize themselves arbitrarily. Thus, the MANET wireless topology may change rapidly and unpredictably. Such a network may operate in a stand-alone fashion or may be connected to a larger Internet.
A MANET consists of mobile platforms called nodes that are free to move about arbitrarily. MANET nodes may be equipped with wireless transmitters and receivers using antennas which may be omnidirectional (broadcast), highly directional (point-to-point), steerable, or some combination thereof. Generally MANETs are bandwidth-constrained variable-capacity links. Often the nodes are energy-constrained since they may be portable and rely on battery power.
An implicit assumption within a MANET is that every node within the network may wish to communicate with every other node within the network. The MANET protocol defines all devices as routers, and then goes about trying to comprehend how each router maintains real time knowledge about the existence of other routers within the network. This becomes an exponential task to manage as the network increases in size. This problem is compounded by the ability of the nodes to dynamically enter or leave the network in an “ad hoc” fashion. The ad hoc nature of the network creates an onerous network management problem, flooding the network with status packages requiring constant updates.
There are a number of postulated causes for MANET network failure. The network updates may not be received fast enough to keep up with dynamic changes. The information about which nodes are currently connected to the network may become so out of date that it is no longer trustworthy. The network updates may consume so much of the available bandwidth that there may be insufficient residual bandwidth for actual data to traverse the network. The battery life of each node may be insufficient because of the volume of update traffic, which requires the node to be almost permanently communicating with other devices in order to obtain network status information. A routing table that contains the information about how to traverse from one node to another may become so large that it may not be stored in the available memory capacity of nodes within the network.
Thus, there is a need for better ways to manage a mobile ad hoc network.